home

Monday, December 5, 2011

SPDY protocol

The new Google SPDY protocol is another attempt to make the web more efficient and reliable. The SPDY protocol introduces an extra layer between HTTP and TCP/IP (actually SSL/TLS) that primarily allows for multiplexing and parallelizing multiple HTTP requests over a single SSL connection.

The SPDY protocol is not some lab exercise but used in production! The Google Chrome browser uses the SPDY protocol (or should we say extension?) to communicate with most Google's applications. SPDY remains mostly a Google thing, with no adoption by other big names (except for Amazon EC2 it seems).

With SPDY, the Chromium browser needs to establish fewer SSL connections. But more importantly, the Chrome browser can launch many HTTP requests in parallel, no longer restricted by a maximum number of TCP/IP connections.

But this made me think: could this have a positive impact on how service consumers are implemented? Similarly to a browser parallizing the retrieval of web content, (web) service consumers should also try to parallize as much as possible.

The HTTP request/response model that underlies web services should not lock us into a synchronous RPC paradigm wherey a requestor blocks waiting for a response. To fully leverage this potential of parallellism, we must move to non-blocking, AJAX like model programming model.

While reading about SPDY, I encountered 2 links worth looking into:
- Recent blog entry by F5 that is a critical review of the SPDY protocol.
- Article that starts with SPDY but goes much further into wild (?) and interesting ideas to re-engineer the workings of the Internet in a more dramatic.